1. Field of the Invention
The invention relates to a water-cooling radiator for a computer chip. In particular, the invention relates to a radiator having a built-in and branched coolant circulation flow path with air-cooling and water-cooling mechanisms.
2. Description of Related Art
Over the years, both the device density and the processing speed of a computer chip (integrated circuit) have increased significantly in keeping up pace with functional enhancement of electronics appliances. Besides that the processing speed has multiplied, the amount of heat generated by the computer chip has also increased. It is an important issue to dissipate heat for a chip application.
Demanded by an urging need to boost performance, computer chips like the CPU (central processing unit), the GPU (graphics processing unit), the northbridge chip, and the RAM (random access memory) have to increase their operating frequencies, resulting in increases in power consumption and heat generation. If the heat generated by the chip cannot be effectively removed thus resulting in a significant increase of temperature, problems such as semiconductor characteristics offset, transistor functional failure, or a computer crash might occur, or even more drastically, a chip burnout.
Generally, dissipation of the heat generated by a computer chip includes the following two steps of: (1) first conducting the heat generated by a computer chip to dissipating fins of a radiator; and (2) then conducting the heat from the dissipating fins to surrounding air. The two steps are both indispensable; if either step encounters a problem, the heat conduction would be affected, which hinders a radiator to dissipate heat effectively. Therefore, a basic design principle for a radiator is maximizing the heat transfer in step (1) and step (2) as a key purpose.
As disclosed in Taiwanese Patent Issue No. 00460773, a conventional air-cooling radiator uses high thermal conductivity of metals to conduct the heat generated by a computer chip to dissipating fins and dissipates the heat into ambient air by natural convection or forced convection with a fan. To increase the amount of heat transfer from the dissipating fins to the surrounding air in step (2), a common improvement is to increase the surface area of the dissipating fins contacting the surrounding air. However, for a heat dissipating body used in the steps, an increase in surface area indicates a decrease in solidity (a measure of the percentage of space taken up per unit volume) and a decrease in the cross area of heat conduction paths, thus relatively affecting the heat transfer from the chip to the dissipating fins in step (1). Conversely, if the solidity of the body is increased to increase the heat transfer in step (1), the surface area is then reduced, hence affecting the heat transfer in step (2). The solution to this dilemma is aimed to accelerate the heat dissipation in step (1) meanwhile increasing the heat dissipating surface and decreasing the solidity. In this regard, a water-cooling radiator has been designed.
The thermal conductivity of water is about twenty-three times that of air; the specific heat per unit mass of water is about seventeen times that of air; and the specific heat per unit volume of water is at least fourteen-thousand times that of air. Therefore, in the case of same contacting area or surface area, a water-cooling radiator has a cooling performance much better than that of an air-cooling radiator, despite having problems in covering the coolant, driving the coolant and preventing leakage of the coolant. Generally, a water-cooling radiator has a more complex structure and has a higher price, so it is less commonly used.
As disclosed in Taiwanese Patent Issue No. M257612, a conventional water-cooling radiator has coolant circulation pipelines on the exterior of a radiator. The coolant is injected into the vicinity of a computer chip to absorb heat, and the heat is brought out by heat convection to expedite the heat transfer in step (1) above and hence improve heat dissipation. Nevertheless, this type of water-cooling radiator has a more complex structure, and the coolant circulation pipelines and the dissipating fins may make an improper contact or have some gaps therebetween, resulting in a lower beat dissipation efficiency.
It is common currently to have to face and resolve the challenge of heat dissipation for a high performance computer chip. Limited by performance, a conventional air-cooling radiator no longer satisfies the heat dissipation requirement for a computer chip of higher processing speed. It is therefore in the respect of processing speed of the computer chip, an unsolved heat dissipation problem would seriously hinder the further development of the computer chip.
Coping to improve the performance of heat dissipation for a computer chip, the invention provides both advantages of an air-cooling radiator and a water-cooling radiator. In other words, the invention provides a simple structure of an air-cooling radiator and a high heat dissipation performance of a water-cooling radiator.